Triangle read by rows, T(n,k) = (k+1)*(n+1)!*(n+k)!/((k+1)!^2*(n-k)!) with n >= 0 and 0 <= k <= n.

Terms

a(0) =1a(1) =2a(2) =2a(3) =6a(4) =18a(5) =12a(6) =24a(7) =144a(8) =240a(9) =120a(10) =120a(11) =1200a(12) =3600a(13) =4200a(14) =1680a(15) =720a(16) =10800a(17) =50400a(18) =100800a(19) =90720a(20) =30240a(21) =5040a(22) =105840a(23) =705600a(24) =2116800a(25) =3175200a(26) =2328480a(27) =665280a(28) =40320a(29) =1128960